Mass Select Users For Editing

Description

I noticed that you can't check a checkbox and select all users in a similar way to mass editing comments/links. I went about creating this. The file contains a new JS function for the user page, I refactored a JS function, and I edited the UI for the edit users page.

Now, when a user clicks the input checkbox it will select all users in that specific role for editing (and unchecking as well).

The only thing to note is when a user adds a user the Ajax response doesn't pass in a class name (which I made the role) which the JS functions depends on. So if a user adds a user and then tries to select all users under that role then it will omit the one user from the Ajax response. I tried editing admin-ajax, but I am so sick of working on this I hope someone else can do it.